96 REPORT OF COMMISSIONERS OF INLAND FISHERIES. 



an experiment made a year ago in our station by Dr. V. E. Emmel, in 

 rearing fourth-stage lobsters to the fifth stage.* Ninety fourth- 

 stage lobsters were put separately into glass jars, one lobster into 

 each jar, and the whole crate of jars submerged in the water about 2 

 feet below the surface. A screen of woven copper wire was placed 

 over the wide mouth of each jar to keep the lobsters from escaping. 

 All these lobsters were found dead twelve hours later. Galvanized 

 copper wire screen was then substituted in a new experiment and in 

 twenty-four hours the whole lot were dead. Finally a cloth screen of 

 bobbinet was used, and out of 75 lobsters which were fed, only 1 died 

 before molting into the fifth stage. Of 15 which were not fed 4 died 

 at the end of a month. These difficulties, if recognized, may in 

 most cases easily be overcome. 



TESTS OF EFFICIENCY. 



The method and apparatus which have been herein described have 

 been developed, as we have said, mainly in connection with the rear- 

 ing of lobsters through their pelagic larval stages. But as proficiency 

 in this work has increased we have come to realize that the method is 

 equally well adapted to the rearing of a great variety of fishes and 

 aquatic invertebrates. 



Hatching and rearing lobsters. — While the hatching of lobster eggs 

 by this method presents no difficulties, and young lobsterlings, after 

 reaching the fourth stage, can also be cared for without the use of 

 special appliances, the larval lobsters, on the other hand, during the 

 three free-swimming stages of two or three weeks' duration, seem to 

 incarnate nearly all the perverse and intractable characteristics 

 which, from the view point of fish culture, are difficult to deal with. 

 They are pelagic and are safe only when floating, yet in confinement 

 they persistently tend to go to the sides and bottom of the inclosure. 

 They are comparatively slow of movement and weak in their instincts 

 of self-preservation and of seeking food, yet their most distressing 



* Report of Rhode Island Commissioners of Inland Fisheries for 1907, page 104. 



